Spray foam insulation
Spray foam insulation is a type of expanding liquid plastic that is sprayed in place to fill cracks, gaps, and voids in a home or building envelope. It is made of two liquid components, an isocyanate and a polyol, that react when mixed to form a foam that expands to fill the space. Spray foam insulation can be used in both new and existing construction.
There are two types of spray foam insulation
OPEN-CELL R-value of 3.5 per inch.
CLOSED-CELL R-value of 7.0 per inch
Choosing the Right Insulation for Your Job
Many people choose to insulate their homes for a variety of reasons. The most common ones are to minimize energy cost, improve environmental conditions as well as noise reduction. There are different types of insulation that can be used, and while some opt to use fiberglass or batt insulation for insulating their residence, it is spray foam that is most effective and provides the most longevity.
There are actually two types of spray foam insulation, and while they both outperform conventional insulations, there are important considerations for when these should be used. The two types of spray foam insulation are open cell and closed cell foam.
A major difference in the value between the two types comes down to the total R-value achieved – the rating assigned to material that identifies resistance to heat flow. The higher the R-value, the more heat resistance you receive. Open cell foam is less dense, comprised of free-flowing air within the spaces where the foam cells have not formed and interlocked. Closed cell foam is far denser, so it is not porous in its composition. The air is therefore trapped inside, as the foam’s cells bind closer together to make a tighter, water-resistant layer, it takes more of such foam to fill the same space that it would take the open cell foam to occupy. Both can be very effective inside a home or building, however closed cell foams are functionally superior when exposed to weather elements outside.
How Open Cell Foam Insulation Is Used?
Because of the porous nature, this insulation is not water-resistant, so it is best used when moisture in the area is less likely. In other words, open cell foam is best used in those areas where there is a much lower chance of water getting to it, or indoors.
Every type of insulation is assigned a particular “R-value” with this number representing how much air the insulation lets through. The higher the R-value, the tighter the pores and more air restrictive it is. Open cell foam insulation has an R-value of 3,5. Beyond letting in less air and preventing heat from escaping, open-cell spray foam is far superior in reducing sound. When used in interior walls, open cell spray foam works well at reducing the noise level, working well as a soundproofing barrier.
How Closed Cell Spray Foam Is Used?
When closed cell spray foam insulation is sprayed, the propelling agent adds an extra insulation layer, raising the R-value of this type of insulation to 7.0. Because this type of foam is not open and porous, it has a sealing attribute that retains the temperature on one side while not allowing the temperature from the other to escape. The closed or sealed nature of the cells improves the moisture resistance and weatherability of the product and once applied gives added strength to the substrate.
For these reasons, closed cell foam works overall better at insulating walls and areas that are located at or below grade, such as basements and crawls spaces. Closed cell foams are often used where increased strength is needed such as commercial roofs. Rainwater can often enter exterior walls, so open cell foam without moisture barriers is not ideal for those spaces as it lets water in through its pores. Closed cell foam can be used on interior walls as well, but the cost of application is usually a deterrent from doing so in non-commercial building spaces. Because it’s more tightly packed, closed cell foam requires more of it to fill a particular space. For money-saving reasons, contractors and customers opt to spray closed cell foam only into exterior walls.
Benefits Of Open Cell And Closed Cell Foam
When the foam is sprayed, it expands into small crevices and cracks in the wall. That means there is an extra layer that blocks heat or cool air from escaping to the outside and reduces the ability of the hot or cold air from the outdoors from entering. In the same sense, the denseness of spray foam blocks out auditory components too, acting as a soundproofing barrier that can keep the indoors of a residence, or even noise level between rooms quiet.
Heat retention and soundproofing are two of the most common reasons for using spray foam, but several others are commonly overlooked. For instance, the tightly sealed outdoor walls create a more resistant barrier to allergens, like pollen, from sneaking through the crevices and cracks. The same logic applies to keeping out unwanted pests like bugs and rodents. They find their way through the small spaces in walls, but with the foam occupying those spaces, especially with closed cell foam material, creatures’ way in is severely restricted.
Foam spray is long-lasting, so once done, it will likely be a very long time before any type of reapplication or change is needed. Then there is the structural component. While there is a building code that assures that walls can bear the load of the rest of the home, acts of nature are not considered. Foam insulation also acts as a binding agent, reinforcing the strength of walls in the cases of heavy snow, powerful winds, and even earthquakes.
Open-cell vs Closed-cell
Open-cell
— Light density, Air barrier, Vapour permeable, High expansion rate, Sound dampening, More affordable compared to closed-cell.
Ideal for
— Garages, bonus rooms, soundproofing, hard-to-reach areas.
Closed-cell
— Medium density, High R-Values , Air barrier , Vapour barrier, Structural Durability
Ideal for
— Below-grade, crawlspaces, roofs , exterior applications.
Air leakage can account for 25-40% of the energy used to heat and cool a typical home.
Traditional insulation leaves space for air to pass through and moisture to build up over time. With fiberglass insulation, 1/3 of air inside a home escapes through the openings in ceilings, walls and floors. Spray Foam Insulation gets into every space—even hard-to-reach gaps, expands to fill it, and cures to a solid fit that eliminates gaps to keep air from escaping.
